The present invention relates to optical disks.
The term “optical disk” is used to mean a disk having at least one face carrying information that is readable by means of a laser while the disk is rotating. The disk may optionally be rewritable. Examples of optical disks include CDs, DVDs, and HD-DVDs.
Also, optical disks comprising a flexible structure defining a face that is readable by means of a laser beam of blue color, together with a paper support for stiffening the flexible structure, are sold by the supplier Sony.
US patent application No. US 2004/0054594 describes an optical disk provided with a radio frequency identification (RFID) device. Other optical disks are described in the following publications: GB 2 341 845, WO 02/075654, and US 2003/0133401.
Application EP-A2-1 291 815 relates to a card for storing data concerning a patient, the card including a chip and a layer of aluminum for storing data. The layer of aluminum is disposed between a layer of plastics material that is sufficiently thick to stiffen the layer of aluminum, and a transparent layer that allows the information stored in the aluminum layer to be read. A layer of paper may be placed on the stiffening layer made of plastics material so that data can be printed thereon, however the layer of paper does not serve to stiffen the layer of aluminum.